MERN JWT Auth System

I need a complete, production-ready authentication module built on the MERN stack. The scope is limited to a single “User” role, yet the code should be flexible enough for future role expansion.

Core requirements
• React (functional components) with colourful, vibrant, fully responsive login and sign-up screens
• Node.js + Express REST API that issues and validates JWTs, hashes passwords with bcrypt, and stores user data in MongoDB (using Mongoose)
• Email-based OTP verification flow on registration
• Google Sign-In as an alternative to the regular form flow
• Cleanly structured GitHub repository with clear commit history and a concise README for local setup and deployment
• Turnaround time: 7–10 days, including one round of polish after initial review

Acceptance will be based on:
1. Seamless sign-up / login, refresh-token cycle, and logout without console errors
2. OTP email received within seconds in a test Gmail account I provide
3. Google OAuth login returning a valid JWT that grants identical user privileges
4. Mobile-first layout passes Lighthouse responsive checks
5. Code passes eslint/prettier rules and runs with npm install && npm start on my machine

Hand-off artifacts will include the GitHub link, .env sample, and a short Loom walkthrough. Feel free to suggest libraries or UI frameworks you trust, as long as the end look stays bright and lively.